The present invention relates to orthopedic cutting blocks or guides and more particularly, to orthopedic cutting blocks or guides for use in making augmentation cuts.
There are currently many different apparatus for use in resecting bone, as well as many different methods of utilizing same. Many of these apparatus are guides or blocks whose purpose is to guide a surgeon in making cuts or resections (e.g.—by utilizing a cutting tool) in a bone. Often times, the ultimate goal in this type of procedure is to provide a bone surface capable of mating with a corresponding surface of an implant or the like. These cutting guides often vary depending upon the type of cutting instruments being used, the bone being resected, or the type of procedure being performed, among other reasons. For example, cutting guides to be used in conjunction with saws or bladed cutting instruments often have slots or grooves formed therethrough and depending upon the specific bone being resected or the implant being implanted, these slots or grooves may be configured and situated differently. Thus, there currently exist many different types of cutting guides in the prior art.
One type of surgery that relies heavily upon the use of cutting guides is surgery involving the knee joint, and its various bone surfaces. During a typical total knee replacement surgery, the surfaces of both the femur and the tibia are resected and fitted with articulating implants in order to restore natural movement of the lower leg with respect to the upper leg. Different cutting blocks may be used during such surgery to, for example, make several different cuts across the distal end of the femur and at least one cut across the proximal end of the tibia. Those of ordinary skill in the art will readily recognize that there exist many different types of these cutting blocks for use during many of the different widely performed primary and revision total knee procedures. However, other problems may exist in the knee joint, which require somewhat different procedures than that of typical total knee surgery.
Often times, either prior or subsequent to an initial knee procedure, the bones of the knee joint will unevenly wear. For example, normal movement of the knee joint requires a relatively specific cooperation between the femur and the tibia. Over time, this cooperation, as well as the constant movement of the bones with respect to one another, will result in normal wear of the bones. However, due to injuries, defects or the like, sometimes, one or both of the distal end of the femur or the proximal end of the tibia will unevenly or unnaturally wear. Frequently, for example, the medial side of the proximal end of the tibia will develop a deeper than usual wear pattern with respect to its lateral side. FIG. 1 of the present application depicts a right tibia 1 exhibiting such a wear pattern 3. It is noted that such wear or degeneration of bone may also occur after an initial total knee surgery has been conducted.
In order to correct these types of defects, surgeons will often perform an augmentation surgery. Typically, this type of procedure entails resecting the entire proximal end of the tibia so that the remaining end exhibits one or more planar surfaces extending across the bone. This type of cut or resection necessarily requires that at least some lesser worn or unworn and otherwise healthy bone (shown in FIG. 1 as section 5 of tibia 1) be removed from the tibia. Thus, the overall bone material in the tibia is reduced, as well as material which may need to be removed in any additional revision surgeries performed on the knee. However, such material is typically replaced through the implantation of a tibial implant and augmentation block. Such surgery using augments is well known in the field.
Typically, a surgeon will utilize a single cutting block, like block 38 shown in FIG. 7, to make cuts on the proximal end of tibia at the different heights of the particular sections. In this regard, a surgeon will typically make a cut across the worn section 3 by utilizing a lower slot, and a cut across the lesser worn section 5 by utilizing one of the higher slots. However, performing such cuts often results in uneven or incorrectly gauged surfaces, which do not exactly match up with the tibial implant and augment to be implanted. For example, often times, the specific cutting slots on a given cutting block may not allow for the creation of cut surfaces that permit proper implantation of the tibial implant and augment. In many cases, this may require the use of additional or different cutting blocks, or may require a surgeon to perform free hand or otherwise approximated cuts.
Therefore, there exists a need for a cutting guide and method which allows for cut surfaces to be formed that are situated so as to permit proper implantation of an implant and augment during a surgery using augments.